Fixing the fuel tank

Looks like a 10 minute fix.

Remove solder blob from bottom hole. Push dent out with a rod. Put back a blob of solder over the hole.

For $120.00 I'd have a crack at un-soldering it a little panel beating and solder it back up again.

If the soldiering is a challenge (it would be for me) I'm sure you have a friend who can assist.

Can you compare yours with the floats in the carbies you borrowed from your mate?

Jarrod

This may sound stupid, but why not try running it with the float installed upside down.

Nothing to loose.

Ok, here we go,
The dent is on the top to one side only and I feel it just may be pushing the needle to one side and not seating. I can hold the needle up with my finger and it only takes the slightest amount to stop the fuel flowing.
By soldering something to the top and pulling might work but I had a total failure years ago trying to re solder the pin hole and it blew the float apart from too much heat and wrote it off.
Having said that, now I know the cause of the blow out so with more care it might be worth a go.
Hot water might be a good option to try but I would want easy acess to a spare float before hand just in case.
Thanks for the link to a float. Looks like one from a Zenith but should be interchangeable. MAybe even a TEA20 float would work as well.
I will have another play with it tomorrow and again if I am still up that creek with out a paddle or a boat I have already been contacted by my mate saying to come and borrow the good carby he has.
Time will tell
Thanks for all the replies and positive ideas on how to go forward, it is appreciated.

In today's episode, we explore the internals of the engine. I pulled the rocker cover off and checked the clearances of the valves. A couple were slightly tight but still had plenty of clearance when running warm. So I went through all of them and checked the gaps and made them as specified. Typical Pommies don't give you a COLD setting only HOT so at the moment they are set cold to the gaps suggested. I lost spark at one stage and went hunting and in the end I looked closely at were the power enters the dizzy. The bolt ran close to ground so I put a short piece of insulation under it and that appears to have solved that problem. I did have a go at the float. I opened the hole at the bottom of the float and used a piece of fencing wire, (the most handiest tool on a farm) to push up the small dent at the top. I did have to bump it a little with a hammer but got it up fairly close. So with the rocker cover off I did a start up and took this video. It still does not run smooth and with out touching anything it occasionally picks up the revs slightly and goes back to running rough again. If I pick the revs up a little the engine still runs rough but not as bad but then spreads the love of oil to everyone nearby.

I also forgot to say in my last thread that there is no blockages in either of the fuel caps so fuel does not get caught up in a vacuum, I can see through them both so it's not starving from that end.

I had a look at my bits,and the float valve is a sealed unit,....but anyway ,my thought was that maybe there are different valves for petrol pump and gravity feed......I know this is so for some other carbys.

Yes the float valve is sealed and done for a very handy reason. If you need to get at the jets or fuel bowl you can leave the throttle body attached to the manifold and when you disconnect the throttle linkage, choke cable, air filter and undo the 4 screws the bottom half drops away for easy access. The float needle has 3 different sizes in the holes that feed the fuel through. This carby uses a 2.0 and there are 1.5 and 1.25 used in smaller carbies. You also have to have this style of captured needle so you can set your fuel level. Remove the main jet and idle jet and by leaving the main jet holder in place it acts as a tube that you can view the fuel level when you hold the body against the top and turn on the fuel but you have to face the bowl towards your self. A simple but effective way of doing it. This needle n seat came with 2 different thickness fibre washers and the thin one seems to allow the fuel level to be at the 3mm below the height of the tube.
Got so much crap running about my head at the moment with this problem and all I can do is keep trying stuff and try them again and again.

The engine is now running far better with room for improvement. I fitted up the borrowed carby and started the engine. It was missing on a number of cylinders but had a huge spark at each plug and only 1 1/2 cylinders appeared to be firing. Swapped over the ones not firing well with 3 old plugs and it this improved things but still not happy. dug out the timing light and removed the cover on the bell housing and turned the engine over to approaching TDC and the marks were coming up. The manual says to put the letter "M" in the centre of the hole, I have no pointer on mine, and at this point the points should be just breaking but mine were opened more than 'just'. So using a test lamp I loosened the distributor bracket and rotated the it back so that the light was on and slowly rotated the distributor until the light just went out. At this stage this is where the manual tells you to set it to and should be 7' BTDC. It started up ok but was occasionally back firing through the exhaust so I moved it a little bit and until the engine sounded as smooth as it could be at this stage. I lock it up at this point and went back around to the carby where on full throttle the engine was not too bad but at idle it was not quite so good and I moved the mixture and got it as good as it could be. Came back after lunch and swapped the carby over to using mine. Started ok, idled sort of, very little black smoke but on full throttle the revs were up and down so I adjusted the spring tension on the throttle linkage and this settled down nicely to a constant running engine at full throttle. Back it off to idle and got a back fire through the exhaust but at least it was now idling with almost no smoke but when I pulled the throttle on full and fast there is a hesitation. This to me is a mixture problem but no matter where I adjust the mixture screw it made little difference but I have found a spot where it is at the least amount. I drove the tractor up and down the drive way but this is not good enough to test it so will do a road run tomorrow and see where I am at.

I did end up with my timing light connected and managed to get the light around the engine to the inspection hole on the opposite side and reading from #1 HT lead I do not see any marks on my flywheel. The same goes on the other 3 leads, any clues on this one?

If you run the motor in the dark (black) you can easily see ignition leakage and flashover.....if its quiet enough you may also hear cracking noise where a lead has a crack or cut.